Primary Bilateral Total Knee Arthroplasty Research Articles

Prediction of postoperative gait speed change after bilateral primary total knee arthroplasty in female patients using a machine learning algorithm

BackgroundAn important aim of total knee arthroplasty is to achieve functional recovery, which includes post-operative increase in walking speed. Therefore, predicting whether a patient will walk faster or slower after surgery is important in TKA, which has not been studied in previous literatures. Who walks faster and who walks slower after TKA? Can we predict these kinds of patients before surgery? HypothesisWhether or not a patient walk faster after total knee arthroplasty can be predicted with preoperative characteristics. Patients and methodsIn this retrospective cohort study, 128 female patients who underwent staged bilateral total knee arthroplasty were analyzed with gait analysis preoperatively and at postoperative two years. These patients were divided into three different groups according to the percentage of gait speed change after total knee arthroplasty: 1) V(+), more than 10% gait speed increase; 2) V(−), more than 10% gait speed decrease; and 3) V(0), those in-between. Gait parameters, mechanical axis angles, WOMAC pain score and Knee Society scores of the two groups (V(+) and V(−)) were compared. Furthermore, a classification model predicting whether a patient walks faster after total knee arthroplasty was designed using a machine learning algorithm. ResultsAfter total knee arthroplasty, average gait speed increased by 0.07m/s from 0.87m/s to 0.94m/s (p<0.001) and gait speed increased in 43.8% of the patients (n=56). However, gait speed decreased in a significant number of patients (n=17, 13.3%). When V(+) and V(−) groups were compared, gait speed, cadence, sagittal/coronal knee range of motion, and Knee Society Function score were lower in the V(+) group before surgery, but became higher after surgery. Gait speed change could be predicted using three variables (preoperative gait speed, age, and the magnitude of mechanical axis angle). The area under the receiver operating characteristic curve of the machine learning model was 0.86. DiscussionAfter total knee arthroplasty, gait speed was maintained or increased in most patients. However, gait speed decreased in a significant number of patients. The machine learning classification model showed a good predictive performance, which could aid in the decision-making and the timing of total knee arthroplasty. Level of evidenceIII; retrospective cohort study.

WHAT IMAGING IS REQUIRED TO PLAN TKA? A COMPARISON BETWEEN EOS AND CT SCAN TO ASSESS CORONAL ALIGNMENT

The emergence of patient specific instrumentation has seen an expansion from simple radiographs to plan total knee arthroplasty (TKA) with modern systems using computed tomography (CT) or magnetic resonance imaging scans. Concerns have emerged regarding accuracy of these non-weight bearing modalities to assess true mechanical axis. The aim of our study was to compare coronal alignment on full length standing AP imaging generated by the EOS acquisition system with the CT coronal scout image.Eligible patients underwent unilateral or bilateral primary TKA for osteoarthritis under the care of investigating surgeon between 2017 and 2022, with both EOS X-Ray Imaging Acquisition System and CT scans performed preoperatively. Coronal mechanical alignment was measured on the supine coronal scout CT scan and the standing HKA EOS.Pre-operative lower limb coronal alignment was assessed on 96 knees prior to TKA on the supine coronal scout CT scan and the standing HKA EOS. There were 56 males (56%), and 44 right knees (44%). The mean age was 68 years (range 53-90). The mean coronal alignment was 4.7 degrees (SD 5.3) on CT scan and 4.6 degrees (SD 6.2) on EOS (p=0.70). There was a strong positive correlation of coronal alignment on CT scan and EOS (pearson0.927, p=0.001). The mean difference between EOS and CT scan was 0.9 degrees (SD 2.4). Less than 3 degrees variation between measures was observed in 87% of knees. On linear regression for every 1° varus increase in CT HKA alignment, the EOS HKA alignment increased by 0.93° in varus orientation. The model explained 86% of the variability.CT demonstrates excellent reliability for assessing coronal lower limb alignment compared to EOS in osteoarthritic knees. This supports the routine use of CT to plan TKA without further weight bearing imaging in routine cases.

Functional outcomes and length of stay with early and high-intensity rehabilitation after simultaneous bilateral total knee arthroplasty.

Length of stay and functional outcomes after total knee arthroplasty (TKA) are related to the timing and intensity of post-operative rehabilitation. To determine the effectiveness of early and high-intensity rehabilitation after simultaneous bilateral TKA. Prospective cohort data of 156 patients (11 men and 145 women; average age 72.0 ± 5.6 years) who underwent simultaneous bilateral primary TKA were analyzed. The intervention group (n= 82) underwent a high-intensity rehabilitation (phase II) after early postoperative standard rehabilitation (phase I) between June 2019 and May 2021. The control group (n= 74) underwent a lower-intensity rehabilitation (phase II) after phase I rehabilitation between July 2017 and May 2019. The timed up-and-go (TUG) test, timed stair climbing test (SCT), 6-minute walk test, isometric knee extensor and flexor strength of both knees, knee flexion and extension range of motion, Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) for pain, stiffness, and functional levels, and the EuroQol five-dimension questionnaire were assessed preoperatively and 6 weeks after TKA. The average length of hospital stay was shortened by 5.7 days (p< 0.001). Phase II rehabilitation started earlier in the intervention group than in the control group (7.7 ± 1.3 vs 13.5 ± 2.0, p< 0.001). Compared with the control group, the intervention group showed significant improvements in the measures of mobility (WOMAC-function and SCT) and strength (isometric strength of both knee extensors and flexors) 6 weeks after TKA by statistically controlling for age and preoperative functional status. This study demonstrated that early and high-intensity rehabilitation could achieve functional improvement and shorten the length of hospital stay.

Long-term outcomes of total knee arthroplasty in patients with windswept deformity

BackgroundThis study compared the functional outcomes, implant survival rates, and complications of total knee arthroplasty (TKA) performed in patients with windswept deformity (WSD) and non-WSD patients over at least 10 years of follow-up. MethodsFrom January 2008 to December 2010, 40 TKAs were performed in 20 patients with WSD (WSD group). Additionally, 60 propensity score-matched patients without WSD who had undergone primary bilateral TKA were chosen for the control group in a three-to-one ratio. Then, the functional outcomes, implant survival rates, and complications of TKA in the two groups were compared. The mean follow-up periods were 10.8 years in the WSD group and 11.5 years in the control group. ResultsThe mean Knee Society knee scores in the WSD and control groups improved from 37.7 to 38.1 points preoperatively to 79.5 and 79.2 points at final follow-up (p = 0.974), while the mean function scores in the WSD and control groups improved from 36.5 to 37.2 points preoperatively to 77.8 and 77.4 points at final follow-up (p = 0.863). Two knees in the WSD group required revision surgery, including one due to septic loosening and one due to aseptic loosening. Five knees in the control group required revision surgery, including three due to septic loosening and two due to aseptic loosening. Kaplan–Meier survivorship analysis with the revision of either component as an endpoint in the WSD and control groups estimated 95.0% and 95.8% chances of survival for 10 years, respectively (p = 0.824). ConclusionsTKA performed in patients with WSD yielded good clinical outcomes and survivorship at least 10 years later. Level of evidenceIV.

Comparison of Operative Times in Primary Bilateral Total Knee Arthroplasty Performed by a Single Surgeon.

Purpose: Prolonged operative time (OT) is associated with adverse complications after total knee arthroplasty (TKA). The purpose of this study was to determine whether preoperative factors, such as sex, age, body mass index, body weight (BW), body height, American Society of Anesthesiologists grade, tibiofemoral angle, hospital for special surgery scores, surgical side, surgical order, and calendar year of surgery, affect OT. Methods: One hundred and nineteen patients (238 knees) with osteoarthritis who underwent staged bilateral primary TKA performed by a single surgeon were evaluated. The medical records of 15 males and 104 females were retrospectively reviewed. All variables were expressed as median (interquartile range). Results: The OT for all TKAs was 57 min (51, 65). The OT on the left side (59 min (52–67)) was longer than that on the right side (55 min (50–62)) (p = 0.015). Multiple regression analysis revealed that longer OT was related to BW (β = 0.488, p < 0.001), calendar year of surgery (β = −0.218, p< 0.001), and operative side (β = −0.151, p = 0.007). The Jonckheere–Terpstra test showed a trend toward decreasing OT with calendar year on the left side (p = 0.037) (surgeon’s non-dominant side), but not on the right (p = 0.795). Body height, BW, and body mass index showed weak correlations (r = 0.212, p = 0.001; r = 0.352, p < 0.001; r = 0.290, p < 0.001, respectively) with OT. Conclusion: Patients with a large physique, and especially obesity, with an affected knee on the surgeon’s non-dominant side may require a longer OT; OT decreased over time.

Comparison of Clinical Outcomes after Total Knee Arthroplasty with and without Patellar Resurfacing in the Same Patients.

BackgroundPatellar resurfacing is performed in total knee arthroplasty (TKA) to improve pain in the anterior compartment of the knee joint and to restore proper coordination and movement of the patellofemoral joint. The purpose of this study was to analyze differences in clinical outcomes according to patellar resurfacing in patients who underwent bilateral TKA.MethodsForty-three patients who underwent bilateral primary TKA with patellar resurfacing on one side only were included. Patellar resurfacing was performed selectively according to the status of the patella cartilage surface. Knee Society score (knee and function), Feller score, Kujala score, and Samsung Medical Center (SMC) score (pain and function) were evaluated.ResultsThere were no significant differences in Knee Society pain and function scores, Feller score, Kujala score, and SMC pain and function scores according to patellar resurfacing. On the comparison of SMC scores, there was no difference except for two questions.ConclusionsIt is advisable not to perform resurfacing on normal patellae. However, in order to apply this result to damaged patellae, comparative studies between resurfaced patellae and damaged patellae are needed.

Enhanced recovery protocol after single-stage bilateral primary total knee arthroplasty decreases duration of hospital stay without increasing complication rates.

With an increasing number of total knee arthroplasty (TKA), protocols for better standard of patient care and shorter duration of hospital stay are necessary. Enhanced recovery (ER) protocols are becoming popular to meet these objectives. The current study aims to evaluate the clinical outcome of fast-track TKA using ER protocol in terms of length of hospital stay, perioperative complications and functional outcomes. Patients undergoing single-stage bilateral primary TKA were prospectively included in the study. All patients went through a pre-defined ER protocol of TKA. Length of hospital stay, readmission rates, pain scores and functional scores of patients operated under ER protocol were compared with another matched historical control-group. Factors delaying the discharge of the patients by 48h after the surgery were noted. We compared 275 patients undergoing single-stage bilateral primary TKA through ER protocol (Group 1) with 190 patients who had undergone bilateral primary TKA before the ER protocol was initiated (Group 2). The length of hospital stay (3.9 ± 2.1days in group 1 and 7.5 ± 3.2days in group 2, p 0.0001) and post-operative pain scores at 12h (5.2 ± 2.9 in group 1 and 5.7 ± 2.1 in group 2, p 0.03) and 24h (4.1 ± 1.6 in group 1 and 4.6 ± 1.4 in group 2, p 0.0005) were found to be significantly better with ER protocol. There was no difference in Oxford knee scores, infection rates, readmissions or mortality between the two groups. ER protocol in single-stage bilateral primary TKA resulted in decreased length of hospital stay without increasing complications and compromising the clinical outcome. It requires an integrated approach and adherence to clinical pathways. Level II, Prospective comparative study.

Advantages of Intra-Articular Tranexamic Acid Injection Following Simultaneous Bilateral Primary Total Knee Arthroplasty

Advantages of Intra-Articular Tranexamic Acid Injection Following Simultaneous Bilateral Primary Total Knee Arthroplasty

Is a Titanium Implant for Total Knee Arthroplasty Better? A Randomized Controlled Study

BackgroundLighter weight and lower modulus are potential advantages of titanium (Ti) implants over cobalt chrome (CoCr) implants in total knee arthroplasty (TKA). This study was conducted to determine whether Ti implants in TKA resulted in better clinical outcomes and radiologic results. MethodsOne hundred and eight patients (216 knees) with knee arthritis warranting bilateral primary TKA were randomly allocated to undergo Ti rotating-platform TKA in one knee and CoCr rotating-platform TKA in the contralateral knee. The mean follow-up period was 5.3 years (range, 1-7 years). The weight of Ti implants was one-third lighter than that of CoCr implants (133.9 g vs 390.1 g, P < .01). Clinical outcomes were evaluated using clinical scores, patient preferences (lightness, comfort, naturalness, and satisfaction), gait analysis (kinetic and kinematic data), range of motion, and degree of pain. Radiologic results were evaluated based on the radiolucent line (RLL), degree of medial tibial bone loss, and loosening as seen on X-ray. ResultsNo significant differences were observed in clinical scores or patient preference. Regarding implant weight, approximately 70% of patients did not perceive the Ti implant as lighter. No significant differences were observed in gait analysis, range of motion, or degree of pain. The RLL was seen in 9% of the Ti implant group and 19% of the CoCr implant group. ConclusionThe lighter Ti implant did not show any clinical benefit over CoCr implants. The lightness of the Ti implant is not sufficient to matter or be noticeable. However, the Ti implant showed lower rate of RLL than the CoCr implant. Level of Evidencelevel I, randomized controlled trial.

Simultaneous Bilateral Primary Total Knee Arthroplasty With TXA and Restrictive Transfusion Protocols: Still a 1 in 5 Risk of Allogeneic Transfusion

BackgroundHistorically, there was up to a 60% risk of blood transfusion for patients undergoing simultaneous bilateral total knee arthroplasty (SBTKA). As such, the goal of this study was to analyze the rate and risk factors for allogeneic blood transfusions in patients undergoing SBTKA with tranexamic acid (TXA). MethodsWe retrospectively identified 475 patients who underwent SBTKA with a double dose TXA regimen at a single institution from 2016 to 2019. Mean age was 65 years. Two hundred fifty-seven patients (54%) were female. Mean body mass index was 30 kg/m2. Drains were utilized in 143 patients (30%). Mean preoperative hemoglobin (Hgb) was 13.7 g/dL. Multivariate logistic regression analysis adjusting for age ≥70 years, sex, body mass index, drain use, and preoperative Hgb of <12.5 g/dL was utilized to identify risk factors for transfusion. ResultsOne hundred six patients (22%) received an allogeneic transfusion, including 28 patients (6%) who received ≥2 units. Multivariate analysis showed that preoperative Hgb <12.5 (OR = 3.99, P < .0001), female sex (OR = 2.34, P = .002), and drain use (OR = 2.13, P = .004) were risk factors for transfusion. Forty-two patients (42/83, 51%) with a preoperative Hgb <12.5 received a transfusion compared with 64 patients (64/392, 16%) with a Hgb ≥12.5 (P < .001). ConclusionPatients undergoing SBTKA with contemporary blood management still have a 1 in 5 rate of allogeneic transfusion. Drain use independently increases transfusion risk by 2-fold and should be avoided. Patients with a preoperative Hgb <12.5 have a transfusion rate of 50% and, as such, should either not undergo SBTKA or have extensive perioperative blood optimization.

Tranexamic acid is associated with decreased transfusion, hospital length of stay, and hospital cost in simultaneous bilateral total knee arthroplasty.

Tranexamic acid (TXA) reduces blood loss and transfusion rates in unilateral total knee arthroplasty (TKA), but there is limited data regarding its efficacy in bilateral TKA. This study reports the impact TXA has on clinical outcomes and hospital cost of care in simultaneous, primary bilateral TKA. The 449 patients were retrospectively reviewed. Primary outcomes included the rates of allogeneic and autologous blood transfusion. Secondary outcomes included hospital length of stay (HLOS), post-hospital discharge disposition, 30-day thromboembolic events (TEE), and mean hospital cost of care. Total direct medical costs were obtained from an institutional research database and adjusted to nationally representative unit costs in 2013 inflation-adjusted dollars. Our study revealed that in patients undergoing simultaneous bilateral TKA, TXA use was associated with reduced allogeneic (OR 0.181, 95% CI 0.090-0.366, p < 0.001) and combined allogeneic and autologous transfusion rates (OR 0.451, 95% CI 0.235-0.865, p = 0.017). TXA was associated with a HLOS reduction of 0.9 days (β-coefficient −0.582, 95% CI −1.008-−0.156, p = 0.008), an increased likelihood of hospital discharge over skilled nursing facility (SNF) (OR 2.25, 95% CI 1.117-4.531, p = 0.023) and reduced total hospital cost of care by 6.45% (p < 0.001), room and board costs by 11.76% (p < 0.001), and transfusion costs by 81.65% (p < 0.001). In conclusion, TXA use in bilateral TKA is associated with lower blood transfusion rates, reduced hospital length of stay, reduced cost of hospital care and skilled nursing facility avoidance.

Interval Between Staged Bilateral Total Knee Arthroplasties Does Not Affect Early Medical or Surgical Complications

BackgroundThe purpose of this study is to evaluate early postoperative surgical and medical complications in patients undergoing staged bilateral total knee arthroplasty (TKA) and determine if the interval to the second stage influences the risk of complications. MethodsA retrospective review was performed from 2016 through 2018 of all staged bilateral primary TKA procedures, yielding a cohort of 1005 patients (2010 TKAs). Four groups were created based on the timing of the second stage: 3 to 6 weeks, 7 to 12 weeks, 13 to 24 weeks, and >24 weeks. Clinical data compared between groups included demographics, knee range of motion, University of California, Los Angeles (UCLA) activity score, Knee Society pain score, Knee Society clinical score, and Knee Society functional score. Postoperative complications within 90 days were evaluated, with complications after the second knee being the primary outcome. ResultsThe mean follow-up after second stage was 10.7 months (range, 3 to 37 months). No significant differences were found between groups in the range of motion, Knee Society pain, Knee Society clinical score, Knee Society functional score, or University of California Los Angeles activity score in either the first or second knee. After the first knee surgery, medical complications were highest in the >24-week group. After the second knee, there were no significant difference in manipulation (P = .9), wound complications (P = .7), venous thromboembolism (P = .8), or other medical complications (P = 1) based on the interval duration. ConclusionThe interval between staged TKA did not affect early medical or surgical complications after the second stage. Early clinical and function results were not different based on timing of the second surgery.

Effect of Manipulation under Anesthesia of the First Knee in Staged Bilateral Total Knee Arthroplasty on Clinical Outcome and Satisfaction.

This study aimed to evaluate whether manipulation under anesthesia (MUA) affect clinical outcome including range of motion (ROM) and patient satisfaction after total knee arthroplasty (TKA). It is hypothesized that MUA improves clinical outcomes and patient satisfaction after primary TKA. This retrospective study analyzed 97 patients who underwent staged bilateral primary TKA. MUA of knee flexion more than 120 degrees was performed a week after index surgery just before operation of the opposite site. The first knees with MUA were classified as the MUA group and the second knees without MUA as the control group. ROM, Knee Society Knee Score, Knee Society Functional Score, Western Ontario and McMaster Universities (WOMAC) score, and patient satisfaction were assessed. Postoperative flexion was significantly greater in the MUA group during 6 months follow-up (6 weeks: 111.6 vs. 99.8 degrees, p < 0.001; 3 months: 115.9 vs. 110.2 degrees, p = 0.001; 6 months: 120.2 vs. 117.0 degrees, p = 0.019). Clinical outcomes also showed similar results with knee flexion during 2 years follow-up. Patient satisfaction was significantly high in the MUA group during 12 months (3 months: 80.2 vs. 71.5, p < 0.001; 6 months: 85.8 vs. 79.8, p < 0.001; 12 months: 86.1 vs. 83.9, p < 0.001; 24 months: 86.6 vs. 85.5, p = 0.013). MUA yielded improvement of clinical outcomes including ROM, and patient satisfaction, especially in the early period after TKA. MUA in the first knee could be taken into account to obtain early recovery and to improve patient satisfaction in staged bilateral TKA.

Asynchronous Bilateral Total Knee Arthroplasty: Predictors of the Functional Outcome and Patient Satisfaction for the Second Knee Replacement

BackgroundThe primary aim of this study is to identify independent preoperative predictors of outcome and patient satisfaction for the second total knee arthroplasty (TKA). MethodsA retrospective cohort of 454 patients undergoing an asynchronous (6 weeks or more apart) bilateral primary TKA were identified from an arthroplasty database. Patient demographics, comorbidities, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Short Form-12 scores were collected preoperatively and 1 year postoperatively. Overall patient satisfaction was assessed at 1 year. ResultsThe 1 year WOMAC pain score (P = .01), and improvement in WOMAC pain (P < .001) and functional (P = .002) scores were significantly lower for the second TKA. Worse preoperative WOMAC pain, function, and stiffness scores were demonstrated to be independent predictors of improvement in the WOMAC pain, function, and stiffness scores, respectively, for both the first and second TKA. The overall rate of satisfaction with the first TKA was 94.0% and 94.7% for the second TKA (P = .67). The rate of satisfaction for the second TKA was 77.8% for patients that were dissatisfied with their first TKA, which was an independent predictor of dissatisfaction (P = .02). ConclusionImprovement in pain and function is less with the second TKA, but the satisfaction rate remains similar. There are common independent predictors for change in the WOMAC score for the first and second TKA; however, the predictors of satisfaction were different with no common factors. Patients that were dissatisfied with their first TKA were more likely to be dissatisfied with their second TKA. Level of Evidence IIPrognostic retrospective cohort study.

Age-Related Functional Decline Following Total Knee Arthroplasty: Risk Adjustment is Mandatory

BackgroundPatient-reported outcome measures (PROMs) are being used increasingly to determine the success of total knee arthroplasty (TKA). Our goal is to investigate whether advanced age is associated with lower PROM scores. MethodsWe used our hospital’s TKA registry to examine the relationship between age and PROMs in all patients 50-90 years of age who underwent unilateral or simultaneous bilateral primary TKA between 2007 and 2011 with a primary diagnosis of osteoarthritis. All 5 domains of the Knee Injury and Arthritis Outcomes Score (KOOS) and the Lower Extremity Activity Scale (LEAS) at baseline, 2 years, and 5 years were collected. The association between age and PROM score was assessed by piecewise linear regression using generalized estimating equations, adjusting for demographics, comorbidity, and baseline score. ResultsSignificant nonlinear relationships among age, KOOS subdomains, and LEAS were found. The placement of the age spline knot was at 70 years for KOOS Symptom and 68 years for KOOS Pain, KOOS Activities of Daily Living (ADL), and LEAS. The KOOS Symptom domain showed a significant worsening between 2-year and 5-year follow-up (P < .05) as patients got older. ConclusionWe found an age-related decline in KOOS Pain, KOOS Symptom, KOOS ADL, and LEAS scores. The best fitting spline knots were at 68 (KOOS Pain, KOOS ADL, and LEAS) and 70 years (KOOS Symptoms), respectively. This demonstrates that there is a critical age at which functional decline begins regardless of the quality of the TKA surgery. Our findings will help surgeons accurately guide patient expectations after TKA based on age. Level of EvidenceLevel II, prognostic study.

Comparison of Functional Outcomes Between the First and Second Knee in Staged Bilateral Total Knee Arthroplasty With Diverse Intervals Between Stages

BackgroundThe objective of the study was to analyze if the length of interval time between stages influenced functional and quality of life outcomes in patients with staged bilateral primary total knee arthroplasty (TKA). MethodsThis is a retrospective comparative study between 93 patients with an interval between stages of 6-8 months (6-month group), 112 of 12-14 months (1-year group), and 108 of 24-26 months (2-year group). Outcome variables were Knee Society scores, Western Ontario and McMaster Universities, Short Form, and patient satisfaction. ResultsOverall, the mean follow-up for the first TKA was 8.2 (range, 7-10) years, and for the second TKA, 6.7 (range, 5-10) years. At last follow-up, functional and patient-related outcomes were similar for both knees, regardless of the interval. However, mental score and patient satisfaction were significantly better for the second than for the first TKA in the 2-year group. Age did not correlate significantly with the functional scores but was significantly correlated with the mental score. ConclusionThe performing staged bilateral TKA with a wide interval between surgeries provided equivalent functional outcomes and quality of life for both knees. Postoperative outcomes were not affected by the length of the time interval between procedures or age. Our results can help the surgeon to inform the patients reliably about what they can expect in the delay of a second knee replaced. Thus, patients could make an informed decision.

A comparative study on effectiveness of patellar resurfacing against non-resurfacing in total knee arthroplasty

To investigate the effectiveness of total knee arthroplasty (TKA) with or without patellar resurfacing. Between March 2013 and August 2015, 30 patients (60 knees) with osteoarthritis who met the inclusion criteria were recruited in the study. Of 30 cases, 24 were male and 6 were female with an average age of 57.2 years (range, 37-65 years). The body mass index ranged from 19.5 to 40.3 kg/m 2 (mean, 28.2 kg/m 2). According to Kellgren-Lawrence grading, there were 8 cases at grand Ⅲ and 22 cases at grand Ⅳ. All patients underwent primary bilateral TKA. The patellar resurfacing was done at the unilateral knee randomly (resurfacing side); the opposite treatment was done at the other side (non-resurfacing side). The indexes of 2 groups were recorded and compared, including the intraoperative blood loss, operation time, knee society score (KSS), "Forgotten Joint" scale (FJS), anterior knee pain, anterior patellar spirant, knee constraint feeling, anterior patellar clunk, muscle power of knee extension, and ability of up and down stairs, weight-bearing flexion, squatting down, cross-legged, knee down, knee extension, and patient satisfaction. Radiographic examination was used to analyze the prosthesis position. The operation time were (126±14) minutes and (112±11) minutes in resurfacing side and non-resurfacing side, respectively, showing significant difference between two sides ( t=5.103, P=0.030); and there was no significant difference in intraoperative blood loss between two sides ( t=3.431, P=0.800). All patients were followed up 2-4 years (mean, 2.6 years). There was no significant difference ( P>0.05) between two sides in KSS clinical and functional scores at preoperation and 6 weeks, 6 months, and 2 years after operation; in visual analogue scale (VAS) score of anterior knee pain at preoperation and 6 weeks after operation; in incidences of anterior patellar spirant, knee constraint feeling, anterior patellar clunk, and muscle power of knee extension at 6 weeks, 6 months, and 2 years after operation; in incidences of disability of up and down stairs, weight-bearing flexion, squatting down, cross-legged, knee down, and knee extension at 6 weeks, 6 months, and 2 years after operation; in ratio of FJS score at 2 years after operation. The VAS scores at 6 months and 2 years after operation in resurfacing group were significantly lower than those in non-resurfacing group ( Z=-1.997, P=0.046; Z=-2.197, P=0.028). Patient satisfaction of resurfacing side was superior to the non-resurfacing side at 6 weeks after operation ( χ2=4.271, P=0.039). Radiographic examination showed no prosthesis loosing occurred. The effectiveness of TKA with patellar resurfacing is better than that with non-resurfacing in patients satisfaction.

Unusual Salmonella typhi periprosthetic joint infection involving bilateral knees: management options and literature review

A 70-year-old Indian woman, who had undergone primary bilateral total knee arthroplasty (TKA) for rheumatoid arthritis 10 months prior, presented with 10 days history of pain, swelling and erythema over...

Tranexamic Acid Effectively Reduces Blood Loss and Transfusion Rates during Simultaneous Bilateral Total Knee Arthroplasty.

Tranexamic acid (TXA) can reduce blood loss and decrease transfusion rates after total knee arthroplasty (TKA). The purpose of our study was to evaluate the efficacy of TXA in a homogenous, consecutive cohort of patients undergoing simultaneous bilateral primary TKA. This was a retrospective study of 50 consecutive patients who underwent bilateral simultaneous primary TKA between 2011 and 2015. Of these, 20 patients received TXA and 30 patients did not receive TXA and served as the control group. Primary outcome measurements were intraoperative estimated blood loss, hemoglobin (Hb) and Hematocrit (Hct) levels on postoperative day (POD) 1 and POD2, and blood transfusion rates. Secondary outcomes included length of stay (LOS), knee flexion/extension range of motion (ROM), and postoperative complications. There was no difference between groups for preoperative Hb and Hct (all p > 0.05). The TXA group demonstrate higher Hb levels at POD1 (11.7 in TXA vs. 10.4 controls; p < 0.001) and POD2 (10.5 in TXA vs. 9.6 controls; p < 0.001), as well as higher Hct levels at POD1 (35.6 in TXA vs. 32.1 controls; p < 0.001) and POD2 (31.9 in TXA vs. 29.3 controls; p < 0.001). There was less percentage variation in Hb levels in the TXA group from preoperative to POD1 (17.7% in TXA vs. 25.7% controls; p < 0.0001) and POD2 (26.1% TXA vs. 31.8% controls; p = 0.019). Similarly, less percentage variation in Hct levels in the TXA group from presurgery to POD1 (17.0% TXA vs. 25.7% controls; p < 0.0001) and POD2 (25.0% TXA vs. 31.3% controls; p = 0.005). A total of 23.3% of patients in the control group required transfusions compared with no patients in the TXA (p = 0.044). There were no differences in LOS, knee ROM, or number of complications. No thromboembolic events occurred. TXA in bilateral simultaneous TKA effectively reduces blood loss, maintains postoperative Hb and Hct levels, and significantly decreases blood transfusion rates. The level of evidence is level III (therapeutic study).

Effects of Unilateral Tourniquet Used in Patients Undergoing Simultaneous Bilateral Total Knee Arthroplasty.

To assess the benefits of use of a tourniquet in one limb in patients undergoing simultaneous bilateral total knee arthroplasty (TKA). A prospective randomized trial was designed to evaluate the outcomes of unilateral tourniquet use during simultaneous bilateral TKA. A total of 52 (36 women and 16 men) patients with osteoarthritis who underwent simultaneous bilateral primary TKA between January 2010 and January 2015 were assigned randomly to tourniquet (TG) or non-tourniquet (NG) groups prior to surgery. Operating time, pain score, range of motion, first active straight-leg raise time, swelling, wound healing, deep vein thrombosis, and Knee Society score were observed. Mean operating time in the TG group was shorter than that in the NG group (P < 0.05). Postoperative pain was measured by a visual analog scale (VAS) and straight-leg raise time, which was lower and shorter in limbs operated without the use of a tourniquet (P < 0.05). In addition, this group had less postoperative swelling and lower incidence of wound complications in the early postoperative period (P < 0.05). There was no significant difference in the range of motion (ROM), deep venous thrombosis incidence, and Knee Society scores between the two groups. Tourniquet use in bilateral TKA can reduce intraoperative time but was associated with a higher incidence of wound complications and larger postoperative knee swelling.